Factors associated with diabetes-related clinical inertia in a managed care population and its effect on hemoglobin A1c goal attainment: A claims-based analysis

BACKGROUND: Despite evidence showing the benefits of treatment intensification following an elevated hemoglobin A1c (A1c), clinical inertia, or failure to establish and/or escalate treatment to achieve treatment goals, is a concern among patients diagnosed with type 2 diabetes (T2DM). Clinical inertia may contribute to increased health care utilization and costs due to poor clinical outcomes in MCOs. OBJECTIVES: To (a) identify factors associated with clinical inertia in T2DM and (b) determine differences in A1c goal attainment between patients who experience clinical inertia versus treatment intensification in a commercially insured population. METHODS: Medical and pharmacy claims data were used to identify commercially insured patients in a regional MCO with a recorded A1c≥8.0% between January 1, 2013, and December 31, 2015. In the 4 months following the first elevated A1c value (index date), patients were classified into 2 groups: treatment intensification or clinical inertia. Treatment intensification was defined as the addition of ≥1 new noninsulin antihyperglycemic medication, the addition of insulin, or a dose increase of any current noninsulin antihyperglycemic medication. Patients were required to have ≥1 follow-up A1c value 6-12 months after the index date and continuous enrollment in the health plan for 12 months before and after the index date. Patients were excluded if they had a diagnosis for gestational diabetes or type 1 diabetes or if they were on insulin in the pre-index period. The primary outcome of attaining A1c<7.0% was compared between groups after propensity score matching (PSM). Factors associated with clinical inertia were identified using logistic regression. RESULTS: 3,078 patients, with a mean (SD) age of 54.4 (10.6) years and a mean (SD) baseline A1c of 9.6% (1.7), were included in the study. Of these, 1,093 patients (36%) experienced clinical inertia. After PSM, 1,760 patients remained; 880 in each group. In the clinical inertia group, 23% of patients achieved an A1c<7.0% in the post-index period, compared with 35% in the treatment intensification group (P<0.001). A greater likelihood of experiencing clinical inertia was associated with baseline treatment with 2 (OR = 1.51, 95% CI = 1.22-2.86; P<0.001) or ≥3 (OR = 1.78, 95% CI = 1.30-2.42; P<0.001) antihyperglycemic medications (vs. none), baseline age ≥65 years (OR=2.11, 95% CI=1.63-2.74; P<0.001), and diagnosis of coronary heart disease (OR = 1.44, 95% CI = 1.10-1.88; P=0.007). A baseline A1c≥9.0% (vs. 8.0%-8.9%) was associated with a lower likelihood of experiencing clinical inertia (OR = 0.56, 95% CI = 0.48-0.66; P<0.001). CONCLUSIONS: More than a third of patients in a commercially insured population with T2DM and a baseline A1c≥8% experienced clinical inertia. Clinical inertia resulted in worse A1c outcomes over the 12-month follow-up period. Results of this study suggest that treatment intensification should be monitored, with efforts made to educate health care providers on strategies aimed at improving glycemic control for high-risk patients.